Simultaneous Estimation of Paracetamol, Ambroxol Hydrochloride, Levocetirizine Dihydrochloride, and Phenylephrine Hydrochloride in Combined Tablet Formulation by First-Order Derivative Spectrophotometry

Paracetamol, ambroxol hydrochloride, levocetirizine dihydrochloride, and phenylephrine hydrochloride are used in combination for the treatment of chronic sinusitis, rhinitis, fever, nasal discharge, sore throat, and wheezing. The present work deals with method development for simultaneous estimation of paracetamol, ambroxol hydrochloride, levocetirizine dihydrochloride, and phenylephrine hydrochloride in tablet formulation by first-order derivative spectrosphotometry. For determination of sampling wavelength, 10 μg/mL of each of paracetamol, ambroxol hydrochloride, levocetirizine dihydrochloride, and phenylephrine hydrochloride was scanned in 200–400 nm ranges and sampling wavelengths were found to be 305.5 nm for paracetamol, 321 nm for ambroxol hydrochloride, 244 nm for levocetirizine dihydrochloride, and 280 nm for phenylephrine hydrochloride in first-order derivative spectrophotometry. In this method, linearity was observed in the ranges of 20–140 μg/mL for paracetamol and 10–70 μg/mL for ambroxol hydrochloride, levocetirizine dihydrochloride, and phenylephrine hydrochloride. The % recovery was within the range between 98 and 102%, and % relative standard deviation for precision and accuracy of the method was found to be less than 2%. The method is validated as per International Conference on Harmonization Guidelines. The method can be successfully applied for the simultaneous analysis of these drugs in pharmaceutical dosage forms.

Extractive Spectrophotometric Determination of Tenofovir Disoproxil Fumarate Using Acidic Triphenylmethane Dyes

Tenofovir disoproxil fumarate is a nucleotide reverse transcriptase inhibitor that has activity against the hepatitis B and HIV viruses. Three simple and sensitive extractive spectrophotometric methods have been described for the assay of tenofovir disoproxil fumarate either in pure form or in pharmaceutical formulations. The developed methods involve formation of colored chloroform extractable ion-pair complexes of the drugs with triphenylmethane dyes, namely, bromothymol blue (BTB), bromophenol blue (BPB), and bromocresol purple (BCP) in acidic medium. The extracted complexes showed absorbance maxima between 410 and 415 nm. Beer’s law is obeyed in the concentration ranges 1.5–25, 1.0–25, and 1.25–25 μg mL−1 with BTB, BPB, and BCP, respectively. The effectc of concentration of dye, pH, and interference of excipients have been studied and optimized. The limits of detection and quantification have been determined. All three methods are validated as per the guidelines of ICH. The methods have been applied to the determination of drug in commercial tablets and results of analysis were validated statistically through recovery studies.

Novel Spectrophotometric Methods for the Determination of Selegiline Hydrochloride in Bulk and Its Pharmaceutical Preparation

A simple and highly selective spectrophotometric method has been developed for the determination of selegiline hydrochloride in bulk and formulations. Method A is based on the oxidation of 3-methyl-2-benzothiazolinone hydrazone in the presence of ceric ammonium sulphate, followed by its coupling reaction with drug to form a colored product having λmax of 629 nm. Method B is based on the coupling reaction of drug with 4-aminoantipyrine to give a new ligand that reacts with copper(II) to give intense bluish red colored chelate which is measured at 539 nm. Beer’s law is obeyed in the range of 10.00–85.00 μg mL−1 with molar absorptivity of 0.98×104 for method A and 20.00–120.00 μg mL−1 with molar absorptivity of 0.94×104 for method B. The optimum reaction condition and the analytical parameters are evaluated. The results obtained indicate that the methods are free from interference of the ingredients; thus they are successfully applied to pharmaceutical formulations.

Fluorescence Spectroscopy Study on the Interaction of Acetal Cleavable Anionic Surfactants and Bovine Serum Albumin

The interactions between bovine serum albumin (BSA) and two cleavable anionic surfactants, sodium 3-[(2-nonyl-1,3-dioxolan-4-yl)methoxy]propane-1-sulfonate (SNPS) and sodium 3,3′-(2-nonyl-1,3-dioxane-5,5-diyl)bis(methylene)bis(oxy)dipropane-1-sulfonate (SNDPS), have been studied by means of fluorescence spectroscopy and thermodynamic analysis. The fluorescence of BSA is quenched via a static quenching mechanism with the addition of the surfactants. The binding constants of the surfactants and proteins have been measured, with KA(SNPS) = 8.71×104 M−1 and KA(SNDPS) = 7.08 × 104 M−1, respectively. The interaction between surfactants and BSA is mainly of hydrophobic nature, based on the number of binding sites, n[n(SNPS) = 1.57, n(SNDPS) = 1.47], and the thermodynamic relationship. These results suggest that SNPS and SNDPS could be effective protein denaturants for protein separation and analysis.

Gamma Emitting Radionuclides in Soils from Selected Areas in Douala-Bassa Zone, Littoral Region of Cameroon

A study of natural radioactivity levels in some composites of eighteen soil samples selected within Douala-Bassa zone of Littoral Region has been evaluated. The samples were analysed using gamma spectrometry based broad energy germanium detector (BEGe 6350). The activity profile of radionuclide shows low activity across the studied areas. The obtained mean values of 226Ra, 232Th, and 40K in the two campuses were 25.48 Bq/kg, 65.96 Bq/kg, and 39.14 Bq/kg for Campus 1 and 24.50 Bq/kg, 66.71 Bq/kg, and 28.19 Bq/kg for Campus 2, respectively. In terms of health analysis, some radiation health hazard parameters were calculated within the two campuses. The mean values of radium equivalent activity were 122.81 Bq/kg and 122.08 Bq/kg, absorbed dose rate in air was 99.13 nGy/h and 98.18 nGy/y, annual outdoor effective dose was 0.12 mSv/y and 0.12 mSv/y, and external health hazard index was 0.34 and 0.33 in Campus 1 and Campus 2, respectively. These health hazard parameters were seen to be below the safe limit of UNSCEAR 2000 except the absorbed dose rate in air and the annual outdoor effective doses which are relatively high compared to the values of 60 nGy/h and 0.07 mSv/y. These results reveal no significant radiological health hazards for inhabitance within the study areas.

Development and Validation of UV Spectrophotometric Method for Simultaneous Estimation of Hesperidin and Diosmin in the Pharmaceutical Dosage Form

A simple, rapid, precise and highly selective spectrophotometric method was developed for simultaneous estimation of Hesperidin and Diosmin in tablet dosage form. This method, involves the measurement of absorbances of Hesperidin and Diosmin at the wavelengths of 285 nm (λmax of Hesperidin) and 268 nm (λmax, of Diosmin). The UV spectra’s of Hesperidin and Diosmin prepared in different solvents water, methanol, and acetonitrile and 0.2 N sodium hydroxide were recorded. These two drugs showed good absorbances when dissolved in 0.2 N NaOH. Hence 0.2 N NaOH was selected as the solvent for the method. Two wavelengths 285 and 268 nm were selected which are λmax of two drugs Hesperidin and Diosmin, respectively. Different concentrations of Hesperidin (5–50 μg/mL) and Diosmin (2–24 μg/mL) and a mixture of Hesperidin and Diosmin were prepared, scanned and absorbances were noted at the two wavelengths were fixed for the study. The method showed good reproducibility and recovery with % RSD less than 2. The LOD of Hesperidin and Diosmin was found to be 0.139 μg/mL and 0.048 μg/ml and LOQ of Hesperidin and Diosmin was found to be 0.42 μg/mL and 0.147 μg/mL, respectively. Thus the proposed method was found to be rapid, specific, precise, accurate and cost effective quality control tool for the routine analysis of Hesperidin and Diosmin in bulk and combined dosage form.

A New Analytical Q-Absorbance Ratio Method Development and Validation for Simultaneous Estimation of Lamivudine and Isoniazid

A new UV spectrophotometric absorption ratio method was developed and validated for the simultaneous estimation of lamivudine and isoniazid. The method involved Q-absorption ratio analysis using two wavelengths, with one being the λmax of lamivudine (272 nm, λ2) and the other being the isoabsorptive point of both drugs (246 nm, λ1). Beer’s law was obeyed in the concentration range between 5 and 30 µg/mL for both lamivudine and isoniazid. The results of analysis have been validated statistically and by recovery studies as per ICH guidelines. The accuracy ranged between 99.65 and 101.91% and Sandell’s sensitivity ranged between 0.0229 and 0.0347 µg/cm2. The method was found to be simple, precise, reproducible, rapid, and economical. Hence, it could be used in the analysis of laboratory samples and marketed formulations containing these two drugs in the future.

A Recent Review on Chemiluminescence Reaction, Principle and Application on Pharmaceutical Analysis

This paper provides a general review on principle of chemiluminescent reactions and their recent applications in drug analysis. The structural requirements for chemiluminescent reactions and the different factors that affect the efficiency of analysis are included in the review. Chemiluminescence application in immunoassay is the new version for this review. Practical considerations are not included in the review since the main interest is to state, through the aforementioned applications, that chemiluminescence has been, is, and will be a versatile tool for pharmaceutical analysis in future years.

Characterization of Arsenic Biotransformation Products from an Open Anaerobic Degradation of Fucus distichus by Hydride Generation Gas Chromatography Atomic Absorption Spectrometry and High Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry

This work reports on the isolation and determination of biotransformation products obtained from the organoarsenic compounds that are present in Fucus distichus when it was subjected to an open anaerobic decomposition by using the Hydride Generation Gas Chromatography Atomic Absorption Spectrometry (HG-GC-AAS) and High Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS). The seaweed and filtrate residues obtained from the open anaerobic degradation procedure were extracted in methanol and partitioned in phenol-ether-water mixtures to obtain water soluble extracts. The water soluble extracts were cleaned up and separated on a gel permeation Sephadex G15 column. Arsenic species concentrations were determined by using HG-GC-AAS. Final characterization of the biotransformation isolates was carried out on HPLC-ICP-MS. Only two arsenic species, 2-dimethylarsinoyl ethanol (DMAE) and dimethylarsinic acid (DMAA), were positively identified in the water soluble extract of the marine brown algae. The two arsenic species are strong intermediate candidates in the biosynthesis of arsenobetaine from oceanic arsenate in marine food webs.

Development and Validation of RP-HPLC Method for Azilsartan Medoxomil Potassium Quantitation in Human Plasma by Solid Phase Extraction Procedure

Simple and rapid reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated using solid phase extraction (SPE) technique for the determination of Azilsartan Medoxomil Potassium (AMP) in human plasma; detection was carried out by photo diode array detector. Chromatographic separation of the analyte AMP was achieved within 7.5 min by Waters symmetry C18 (4.6 × 250 mm, 5 µm) column, mobile phase was 25 mM ammonium acetate buffer (pH 5.5): acetonitrile 55 : 45 v/v, flow rate was 1.0 mL/min, and the detection was carried out at 254 nm. Calibration curve was linear (r2 > 0.9985) in the range of 1.0–9.0 µg/mL, limit of detection (LOD) and limit of quantitation (LOQ) were 0.150 µg/mL and 0.400 µg/mL, respectively, and intra- and interday deviations were between 1.53–8.41% and 1.78–4.59%, respectively. The overall mean recovery of AMP was 92.35%. No any endogenous constituents were found to interfere at retention time of the analyte. This new RP-HPLC method was successfully validated and may be applied to conduct bioavailability and bioequivalence studies of AMP.